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NEBULAR THEORY

NEBULAR THEORY. http:// Formation of the solar system. Two important features . FIRST: all the planets orbit in nearly the same flat, disk-like region SECOND: all the planets orbit in the same direction around the Sun These two features are important clues to how the solar system formed.

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NEBULAR THEORY

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  1. NEBULAR THEORY

  2. http://Formation of the solar system

  3. Two important features • FIRST: all the planets orbit in nearly the same flat, disk-like region • SECOND: all the planets orbit in the same direction around the Sun • These two features are important clues to how the solar system formed.

  4. A Giant Nebula • Big cloud of gas and dust • Made mostly of hydrogen and helium • Contained heavier elements as well • Gravity caused the nebula to contract • May have come from material leftover from the big bang or from previous supernovas

  5. In the Nebular Hypothesis, a cloud of gas and dust collapsed by gravity begins to spin faster because of angular momentum conservation

  6. The competing forces associated with gravity, gas pressure, and rotation, the contracting nebula begins to flatten into a spinning pancake shape with a bulge at the center.

  7. As the nebula collapses further, instabilities in the collapsing, rotating cloud cause local regions to begin to contract gravitationally. These local regions of condensation will become the Sun and the planets, as well as their moons and other debris in the Solar System.

  8. Formation of the Sun • Sun first object to form in the solar system • Gravity pulled matter together to the center of the disk • Density and pressure increased • Nuclear fusion reactions began

  9. Formation of the planets • The outer parts of the disk were cooling off • Small pieces of dust started clumping together • Clumps collided and combined with other clumps • Larger clumps attracted smaller clumps with their gravity • Eventually, all these pieces grew into the planets and moons that we find in our solar system today

  10. The outer planets Jupiter Saturn Uranus Neptune • Condensed from lighter materials such as • Hydrogen • Helium • Water • Ammonia • Methane It is so cold by Jupiter and beyond that these materials can form solid particles

  11. The inner planets Mercury Venus Earth Mars • Formed from denser elements • Iron • Silicon • Magnesium • Sulfur • Aluminum • Calcium • Nickel These elements are solid even when close to the Sun

  12. Radiometric Dating • Half-life is the common way to describe the length of time it takes for half the atoms in a particular element to decay • To find a radioactive date the object being dated must contain a radioactive element • Uranium-235 – half-life 704 million years • Carbon 14 – half-life 5720 years • The elements decay by emitting a small part of the atom.

  13. Radiometric Dating Continued • As the element decays it becomes something new • Determining the ratio of the radioactive element in the sample, it can be determined how long that item has been around.

  14. ­As soon as a living organism dies, it stops taking in new carbon. • The ratio of carbon-12 to carbon-14 at the moment of death is the same as every other living thing, but the carbon-14 decays and is not replaced. • The carbon-14 decays with its half-life of 5,700 years, while the amount of carbon-12 remains constant in the sample. • By looking at the ratio of carbon-12 to carbon-14 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of a formerly living thing fairly precisely.

  15. Age of the solar system • Based on the age of the oldest meteorites and radiometric dating the age of the solar system is calculated to about 4.56 billion years

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